1. Field of the Invention
The present invention relates to a computer program product for accessing a database, a computer-readable recording medium in which the program is recorded, and a database operating method. More particularly, the present invention relates to a database access program product which can be easily applied to a process adapted to business operations, a computer-readable recording medium in which the program is recorded, and a database operating method.
2. Description of the Background Art
Conventionally, in system development using a computer, reduction in development cost, shortening of delivery, and improvement in quality are important subjects. In order to achieve the subjects, attempts such as shift from a design method centering on procedures to a design method centering on data, introduction of an RAD (Rapid Application Development) method, and component programming have been made and certain effects are obtained.
For example, productivity is largely improved by introduction of a design development method centering on data. According to the RAD method, a development cycle can be shortened by building a prototype in accordance with a request of the user, recognizing the request of the user more specifically on the basis of a result of the prototyping, and correcting the prototype. As a result, in a system in which the RAD method is introduced, mainly, shortening of the periods of external designing and detailed designing and reduction in cost can be achieved. As a result, the proportion of the phase of program generation is becoming relatively large in the whole system development.
Recently, the number of cases of employing an intranet for a development platform of a backbone system of a company is increasing. In a networked company, it is efficient to construct a backbone system by using an application server. Typically, in system development of an application server, a tag language which is an extension of the HTML (HyperText Markup Language) is used. The tag language is easy to learn and is evaluated as an intranet development tool with high productivity.
However, as the environments of companies are becoming tougher, requirements for system development are becoming higher. Concretely, as the business cycle of a company is being shortened, further shortening of delivery is requested. A company capable of providing a product at lower cost is advantageous.
Since the proportion of the phase of program generation in system development is becoming relatively large, it is important to improve the productivity in the phase. It seems to be most efficient to promote component programming.
The component programming decreases the number of processes necessary for system development and contributes to enhancement of competitiveness of system development from the viewpoints of reduction in a period necessary for the system development and reduction in the cost of the system development. By using only a sufficiently reliable program as a component, the component programming can contribute to improvement in quality of a system. Therefore, it is important to perform component programming efficiently and built an application program by efficiently combining components prepared by the component programming.
However, the function of component programming of the tag language conventionally used for development of an intranet system is weak. Consequently, as long as the conventional tag language is used as it is, it is obvious that improvement of productivity cannot be expected so much.
FIG. 18 is a block diagram showing the configuration of a general system of an intranet using a database (DB). Referring to FIG. 18, a general intranet 600 includes an application server 612, a DB server 614 and a plurality of client PCs 616 which can perform communication with each other via a network 610 by using a protocol called HTTP (Hyper Text Transfer Protocol).
On client PC 616, a general browser 630 operates.
On DB server 614, an RDBMS (Relational DataBase Management System) 622 operates.
On application server 612, a WWW server 618 operates. The “WWW” is an abbreviation of “World Wide Web”. The substance of WWW server 618 is a Java (R) servlet engine 620. Java (R) servlet engine 620 supplies information (HTML source) for forming a screen used to access RDBMS 622 to browser 630 in accordance with a request given from browser 630 of client PC 616 via network 610. Browser 630 displays the screen and returns information entered by the user to Java (R) servlet engine 620. Java (R) servlet engine 620 accesses RDBMS 622 in accordance with information given and returns the HTML source for displaying a result to browser 630. Browser 630 displays the result, thereby responding to the request of the user.
In such a manner, intranet 600 processes requests from the plurality of client PCs 616 by WWW server 618 which operates on application server 612 and returns the result to the browser on each client, thereby performing a business process using RDBMS 622.
In the case of developing a program adapted to a number of business operations, screens to be displayed on the browser have to be generated one by one. In this case, by copying a necessary part in a business program generated and modifying only different parts, another business program can be generated. However, in the case where a bug is found in the original business program, all of the generated business programs have to be checked in order to remove the bug.
In order to avoid the problem, a component common to business programs is used as a module and called as a so-called subroutine. In the case of using the common component as a module, it is sufficient to correct only the module including the bug and it is unnecessary to correct a higher-order business program using the module.
However, a program is conventionally designed in modules on the unit basis of a series of processes for accessing RDBM 622, such as a process for displaying a screen used to input conditions for access, a process of accessing RDBMS 622 on the basis of the inputted conditions, and a process of displaying data obtained as a result of the access. When a series of processes is designed as a module, the use of the module is limited to the series of the processes and a problem such that general versatility cannot be obtained occurs.
Although it is also possible that a series of processes is divided into a plurality of parts and the parts are respectively modularized in order to give general versatility, the number of the modules generated increases and it causes a problem such that efficiency of generating a business program deteriorates.